JP2003329580A - Measurement device and measurement chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformly adjust temperature to a measurement chip in a measurement device using an evanescent wave. <P>SOLUTION: The measurement device is composed of a measurement chip 9, a holder 80 for holding a measurement chip 9, and a laser light source 14 generating an optical beam 13, an incident optical system 15 for entering the light beam 13 into the measurement chip 9, a photodetector 17 for detecting light strength by receiving the light beam 13 reflected with the interface 10b of the measurement chip 9. In the measurement chip 9, the holder 80 is formed with a member with a high thermal conductivity, to which temperature adjusting means is provided. Heat is uniformly conducted from the whole of the measurement chip 9 with arranging the inner wall of the holder 80 so as to plane contact it to the side surface of the measurement chip 9 (a sheath 70) or a bottom surface thereof. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the total reflection of a light beam at the interface between a thin film layer in contact with a sample and a dielectric block to generate an evanescent wave, which causes changes in the intensity of the totally reflected light beam. The present invention relates to a measuring device using an evanescent wave for measuring a value and analyzing a sample, and a measuring chip used in this device.

[0002]

2. Description of the Related Art In a metal, free electrons oscillate collectively to generate compression waves called plasma waves. And, the quantized compression wave generated on the metal surface is
It is called surface plasmon.

Conventionally, various surface plasmon measuring devices have been proposed which analyze the characteristics of a substance to be measured by utilizing the phenomenon that the surface plasmon is excited by a light wave.
Among them, one that is particularly well known is one that uses a system called Kretschmann arrangement (see, for example, JP-A-6-167443).

A surface plasmon measuring apparatus using the above system is basically a dielectric block formed in a prism shape, for example, and is contacted with a substance to be measured such as a sample liquid formed on one surface of the dielectric block. A metal film, a light source that generates a light beam, and an optical system that causes the light beam to enter the dielectric block at various angles so that total reflection conditions can be obtained at the interface between the dielectric block and the metal film. When,
The light detecting means is provided for measuring the intensity of the light beam totally reflected at the interface to detect the state of surface plasmon resonance, that is, the state of attenuation of total reflection.

In order to obtain various incident angles as described above, a relatively thin light beam may be incident on the interface by changing the incident angle, or may be incident on the light beam at various angles. A relatively thick light beam may be incident on the interface in a convergent light state or a divergent light state so as to include the component. In the former case, the light beam whose reflection angle changes according to the change of the incident angle of the incident light beam is detected by a small photodetector that moves in synchronization with the change of the reflection angle, or the direction of change of the reflection angle. It can be detected by an area sensor extending along. On the other hand, in the latter case, each light beam reflected at various reflection angles can be detected by an area sensor extending in a direction in which all the light beams can be received.

In the surface plasmon measuring device having the above structure, when a light beam is incident on the metal film at a specific incident angle of a total reflection angle or more, an evanescent light having an electric field distribution in the substance to be measured in contact with the metal film. A wave is generated, and the surface plasmon is excited at the interface between the metal film and the substance to be measured by this evanescent wave. When the wave vector of the evanescent light is equal to the wave number of the surface plasmon and the wave number matching is established, both are in a resonance state and the energy of the light is transferred to the surface plasmon, so that at the interface between the dielectric block and the metal film. The intensity of the reflected light sharply decreases. This decrease in light intensity is generally detected as a dark line by the light detecting means. Note that the above resonance occurs only when the incident beam is p-polarized. Therefore, it is necessary to set in advance that the light beam is incident as p-polarized light.

If the wave number of the surface plasmon is known from the incident angle at which the attenuated total reflection (ATR) occurs, that is, the attenuated total reflection angle θ _SP , the permittivity of the substance to be measured can be obtained. That is, assuming that the wave number of the surface plasmon is K _SP , the angular frequency of the surface plasmon is ω, the speed of light in vacuum is c, and the dielectric constants of the metal and the substance to be measured are ε _m and ε _s , respectively, the following relationships are established.

[0008]

[Equation 1] That is, by knowing the attenuated total reflection angle θ _SP , which is the incident angle at which the intensity of the reflected light decreases, it is possible to obtain the characteristic relating to the dielectric constant ε _{s of the} substance to be measured, that is, the refractive index.

In this type of surface plasmon measuring device, as disclosed in Japanese Patent Laid-Open No. 11-326194, an array is disclosed for the purpose of measuring the attenuated total reflection angle θ _SP with high accuracy and a large dynamic range. It has been considered to use a light detection means in the shape of a circle. The light detecting means is formed by arranging a plurality of light receiving elements in a predetermined direction, and is arranged so that different light receiving elements receive the components of the light beam totally reflected at various reflection angles at the interface. It is a thing.

In that case, there is provided a differentiating means for differentiating the photodetection signal output by each light receiving element of the array of light detecting means with respect to the arrangement direction of the light receiving element, and the differentiating means outputs this differentiating means. A property related to the refractive index of the substance to be measured is often obtained based on the value.

Further, as a similar measuring device utilizing the attenuated total reflection (ATR), for example, "Spectroscopic Research" Vol. 47, No. 1 (1998), pages 21 to 23 and 26 to 27.
Leakage mode measuring devices described on the page are also known. This leak mode measuring device is basically a dielectric block formed, for example, in a prism shape, a clad layer formed on one surface of the dielectric block, and a clad layer formed on the clad layer for contact with a sample solution. An optical waveguide layer, a light source for generating a light beam, and the light beam at various angles with respect to the dielectric block so that total reflection conditions can be obtained at the interface between the dielectric block and the cladding layer. The optical system is configured to be incident, and a light detection unit that measures the intensity of the light beam totally reflected at the interface and detects the excited state of the guided mode, that is, the attenuated total reflection state.

In the leak mode measuring device having the above structure,
When a light beam is incident on the cladding layer through the dielectric block at an angle of incidence equal to or more than the total reflection angle, only light with a specific incident angle having a specific wave number is transmitted in the optical waveguide layer after passing through the cladding layer. It propagates in the guided mode. When the guided mode is excited in this manner, most of the incident light is taken into the optical waveguide layer, so that the total reflection attenuation occurs in which the intensity of the light totally reflected at the interface sharply decreases.
Since the wave number of the guided light depends on the refractive index of the substance to be measured on the optical waveguide layer, the refractive index of the substance to be measured and the related measured substance to be measured can be obtained by knowing the specific incident angle at which attenuation of total reflection occurs. The properties of the substance can be analyzed.

In this leak mode measuring device as well,
In order to detect the position of the dark line generated in the reflected light due to the attenuation of the total reflection, the above-mentioned array-shaped light detecting means can be used, and in addition to that, the differentiating means is often applied.

The surface plasmon measuring device and the leak mode measuring device described above are sometimes used in random screening to find a specific substance that binds to a desired sensing substance in the field of drug discovery research and the like. A sensing substance is fixed as the substance to be measured on the thin film layer (a metal film in the case of a surface plasmon measuring device, a clad layer and an optical waveguide layer in the case of a leaky mode measuring device), and various sensing substances are fixed on the sensing substance. A sample solution in which a test object is dissolved in a solvent is added, and the angle of the above-described attenuated total reflection angle θ _SP is measured every predetermined time.

If the analyte in the sample solution binds to the sensing substance, this binding causes the refractive index of the sensing substance to change over time. Therefore, the attenuated total reflection angle theta _SP was measured every predetermined time, and it is determined whether or not a change in the attenuated total reflection angle theta _SP occurs, measure a binding state between a test substance and a sensing substance Then, based on the result, it can be determined whether or not the analyte is a specific substance that binds to the sensing substance.
Examples of such a combination of the specific substance and the sensing substance include an antigen and an antibody, or an antibody and an antibody. Specifically, a rabbit anti-human IgG antibody can be immobilized on the surface of the thin film layer as a sensing substance, and a human IgG antibody can be used as the specific substance.

It should be noted that the angle itself of the attenuated total reflection angle θ _SP does not necessarily have to be detected in order to measure the binding state between the analyte and the sensing substance. For example, it is also possible to add a sample solution to the sensing substance, measure the angle change amount of the total reflection attenuation angle θ _SP after that, and measure the binding state based on the magnitude of the angle change amount. In the case of applying the above-mentioned array-shaped light detecting means and the differentiating means to the measuring apparatus using the attenuated total reflection, the variation amount of the differential value reflects the angular variation amount of the attenuated total reflection angle θ _SP . Therefore, the binding state between the sensing substance and the analyte can be measured based on the amount of change in the differential value. (Patent application 20 by the applicant
No. 00-398309) In such a measurement method and apparatus using attenuation of total reflection, a cup-shaped or petri dish-shaped measurement chip in which a sensing substance is fixed on a thin film layer formed in advance on the bottom surface is used as a solvent. A sample liquid consisting of the subject is dropped and supplied, and the above-described attenuated total reflection angle θ
The angle change amount of _SP is measured.

The applicant of the present invention makes it possible to measure a large number of samples in a short time by sequentially measuring a plurality of measuring chips mounted on a turntable or the like. Device as Japanese Patent Laid-Open No. 2001-3
It is proposed by Japanese Patent No. 30560.

The applicant of the present invention filed Japanese Patent Application No. 2001-397.
No. 411 also proposes a measuring device using attenuated total reflection that performs measurement using a measuring chip provided with a plurality of sample liquid holding portions. By using the measuring device having such a configuration, it is possible to simultaneously measure many samples without moving the measuring chip.

[0019]

By the way, in the case of using a measuring device such as a surface plasmon resonance measuring device or a leak mode sensor, for example, in the case of measuring an enzyme reaction in the field of drug discovery research, etc. The enzyme used for is ultimately used in the human body,
Further, in general, the enzymatic reaction becomes active at 35 to 40 ° C, so it is desirable to control the temperature of the sensing substance and the sample solution to 35 to 40 ° C, which is a temperature close to that of the human body, and perform the measurement.

As described above, generally, there is an optimum temperature environment for measuring each substance, usually 4 to 40 ° C.
It is desirable to be able to adjust the temperature within a certain range, but at present, the above measuring device is operated at room temperature, and since temperature adjustment is not performed, it cannot be said that it is the optimum measurement environment.

Further, the refractive index of the sensing substance and the sample liquid changes depending on the temperature. Therefore, if sample liquids having different temperatures are dropped onto the sensing substance, a measurement error will occur when the total reflection attenuation angle θ _SP is measured due to the difference in refractive index due to the temperature difference between the two.

As described above, in the measuring apparatus such as the surface plasmon resonance measuring apparatus and the leak mode sensor, the temperature of the measuring chip that receives the sensing substance and the sample solution has a great influence on the measurement result.

Therefore, it is desirable to adjust the temperature of the measuring chip. However, since the dielectric block of the measuring chip is generally molded with transparent resin or glass, a temperature adjusting means such as a heater is provided around the measuring chip. Even if they are arranged, there is a problem that the temperature cannot be uniformly adjusted for the entire measuring chip and a temperature gradient is generated in the measuring chip.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a measuring device capable of adjusting the temperature of the measuring chip substantially uniformly and a measuring chip used in this device. To do.

[0025]

A first measuring device according to the present invention comprises a dielectric block, a thin film layer formed on one surface of the dielectric block, and a sample holding mechanism for holding a sample on the surface of the thin film layer. A measurement chip provided, a light source for generating a light beam, and a light beam for the dielectric block,
In a measuring device comprising an incident optical system for making an incident angle at which the total reflection condition is obtained at the interface between the dielectric block and the thin film layer, and a photodetecting means for measuring the intensity of the light beam totally reflected at the interface. An optical window provided with a holder configured to be in surface contact with the dielectric block and holding the measurement chip, the holder having a higher thermal conductivity than the dielectric block, the holder being disposed at least on the optical path of the light beam. When,
It is characterized in that it is provided with a temperature adjusting means for adjusting the temperature of the measuring chip via a holder.

The second measuring apparatus according to the present invention comprises a dielectric block, a thin film layer formed on one surface of the dielectric block, and a sample holding mechanism for holding a sample on the surface of the thin film layer. A chip, a light source that generates a light beam, an incident optical system that causes the light beam to enter the dielectric block at an angle of incidence at which the total reflection condition is obtained at the interface between the dielectric block and the thin film layer, and at the interface A measuring device comprising a light detecting means for measuring the intensity of the totally reflected light beam, comprising an enclosing member for spatially isolating the measuring chip from the outside, and the enclosing member is arranged at least on the optical path of the light beam. The optical window and the temperature control means for controlling the temperature inside the surrounding member are provided.

As the measuring device as described above, the above-mentioned surface plasmon measuring device using a metal film as the thin film layer, a clad layer formed on one surface of the dielectric block,
There is the above-mentioned leaky mode measuring device which uses a layer composed of an optical waveguide layer formed on the clad layer as the thin film layer.

In the measuring device according to the present invention, there are various methods for measuring the intensity of the light beam totally reflected at the interface by the light detecting means to analyze the sample. For example, the light beam is totally reflected at the interface. The intensity of the light beam totally reflected by the interface is measured at each position corresponding to each incident angle, and the position (angle) of the dark line generated by the attenuated total reflection is measured. Sample analysis may be carried out by detecting, DVNoort, K.johansen, C.-F.Ma.
ndenius, Porous Gold in Surface Plasmon Resonance
As described in Measurement, EUROSENSORS XIII, 1999, pp.585-588, light beams with a plurality of wavelengths are made incident at an incident angle at which total reflection conditions are obtained at the interface, and total wavelength is obtained at the interface for each wavelength. The sample analysis may be performed by measuring the intensity of the reflected light beam and detecting the degree of attenuation of total reflection (position and degree of dark line) for each wavelength.

[0029] In addition, PINikitin, ANGrigorenko, AAB
eloglazov, MVValeiko, AISavchuk, OASavchuk, Sur
face Plasmon Resonance Interferometry for Micro-Ar
rayBiosensing, EUROSENSORS XIII, 1999, pp.235-238
The light beam is incident at an angle of incidence such that total internal reflection conditions are obtained at the interface, and a portion of the light beam is split before the light beam enters the interface; The sample analysis may be performed by causing the divided light beam to interfere with the light beam totally reflected at the interface and measuring the intensity of the light beam after the interference.

In the above second measuring device, the surrounding member is
It is desirable to be composed of a member having a high heat insulating property such as resin or glass.

The measuring chip according to the present invention is a measuring chip used in the above-mentioned measuring device according to the present invention, in which a sheath composed of a member having a larger heat capacity than that of the dielectric block is provided on the outer surface of the dielectric block. It is characterized by being present.

[0032]

In the first measuring device according to the present invention, a holder made of a member having a higher thermal conductivity than the dielectric block, which is in surface contact with the dielectric block and holds the measuring chip, is provided. By adjusting the temperature of the measuring chip through the holder by the temperature adjusting means provided in the holder, it is possible to conduct heat uniformly from a wide area of the measuring chip to the measuring chip. It is possible to adjust the temperature substantially uniformly.

Further, in the second measuring apparatus according to the present invention, an enclosing member which spatially isolates the measuring chip from the outside is provided, and the temperature inside the enclosing member is adjusted by the temperature adjusting means provided in the enclosing member. With this, heat can be uniformly conducted to the measuring chip from a wide range of the measuring chip, so that the temperature of the entire measuring chip can be adjusted substantially uniformly.

Furthermore, the measuring chip according to the present invention is a measuring chip used in the above-mentioned measuring device, wherein a sheath constituted by a member having a heat capacity larger than that of the dielectric block is provided on the outer surface of the dielectric block for measurement. Since the heat capacity of the entire chip is increased, the temperature fluctuation of the measurement chip can be reduced.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. The measuring apparatus according to the first embodiment of the present invention is a surface plasmon measuring apparatus capable of simultaneously analyzing a plurality of samples by making light beams incident on a plurality of dielectric blocks in parallel. FIG. 1 is a plan view showing a schematic configuration of the surface plasmon measuring apparatus of the present embodiment, and FIG. 2 shows a side surface shape of the surface plasmon measuring apparatus.

The surface plasmon measuring device 101 comprises a plurality of surface plasmon measuring units 101 having the same structure.
A, 101B, 101C ...

The configuration of each measuring unit will be described by omitting the symbols A, B, C ... Representing the individual elements. Each measuring unit includes a measuring chip 9, a holder 80 for holding the measuring chip 9, a laser light source 14 which is a light source for generating a light beam 13, and an incident optics for making the light beam 13 incident on the measuring chip 9. The system 15 and the collimator lens 16 which collimates the light beam 13 reflected by the measuring chip 9 and emits it toward the photodetector 17.
And the light beam 1 emitted from the collimator lens 16
3, a photodetector 17 for receiving 3 to detect the light intensity, a differential amplifier array 18 connected to the photodetector 17, a driver 19 connected to the differential amplifier array 18, and a driver 1
And a signal processing unit 20 composed of a computer system or the like.

The dielectric block 10 of the measuring chip 9 is made of a transparent resin, and as shown in FIG. 3, a plurality of surface plasmon measuring units 101A, 1 adjacent to each other.
01B, 101C ... Are integrally formed with the dielectric block of the measurement chip. On the upper surface 10a of the dielectric block 10, each surface plasmon measuring unit 101A,
Sample liquid 1 is provided at a plurality of positions corresponding to 101B, 101C ,.
A concave portion 10c that functions as a sample holding mechanism for storing 1 is provided.

At the bottom of each recess 10c, for example, gold, silver,
A metal film 12 which is a thin film layer made of copper, aluminum or the like is provided. A sensing medium 30 described below may be further provided on the metal film 12.

Further, on the outer surface of the dielectric block 10, a sheath 70 made of a member such as metal having a larger heat capacity than the dielectric block 10 is provided. The inner wall of the sheath 70 is in surface contact with the side surface and the bottom surface of the dielectric block 10. Further, on the side wall of the sheath 70, an opening 70a is provided at a position corresponding to the optical path of the light beam 13. By providing the sheath 70, the heat capacity of the entire measuring chip 9 is increased, so that the temperature fluctuation of the measuring chip 9 can be reduced. Therefore, when carrying the measuring chip 9 whose temperature is adjusted by an external incubator or the like (not shown) for setting in the measuring device, it is possible to carry the temperature-controlled temperature while maintaining it.

The holder 80 has a high thermal conductivity, for example, A
It is composed of members such as 1 and Bs. The inner wall of the holder 80 is in surface contact with the side surface and the bottom surface of the measuring tip 9 (sheath 70). Also, on the side wall of the holder 80,
The opening 80a is provided at a position corresponding to the optical path of the light beam 13.
Is provided. Further, on the bottom surface of the holder 80, a Peltier element 81 is provided as a temperature adjusting means.

A heat sink 82 is fixed to the lower surface of the Peltier element 81. Further, the Peltier element 81 is connected to the controller 83, and this controller 83
Controlled by.

With the holder 80 having such a structure, the measuring chip 9 can be measured from a wide area of the measuring chip 9.
Since it is possible to conduct heat evenly, the temperature of the entire measuring chip 9 can be adjusted substantially uniformly.

The incident optical system 15 has a collimator lens 15a for collimating the light beam 13 emitted from the laser light source 14, and a condenser for converging the collimated light beam 13 toward the interface 10b. It is composed of a lens 15b.

Since the light beam 13 is condensed by the condensing lens 15b as described above, it contains components that are incident on the interface 10b at various incident angles θ. The incident angle θ is set to an angle equal to or larger than the total reflection angle. Therefore, the light beam 13 totally reflected at the interface 10b contains components totally reflected at various reflection angles. The incident optical system 15 directs the light beam 13 into the interface 10b.
The light may be incident in a defocused state without being condensed in a point shape. By doing so, the interface 10b
Since the light beam 13 is totally reflected in the wider area above, the detection error of the attenuated total reflection state is averaged, and the measurement accuracy of the attenuated total reflection angle can be improved.

The light beam 13 is incident on the interface 10b as p-polarized light. In order to do so, the laser light source 14 may be arranged in advance so that the polarization direction thereof is the above predetermined direction. In addition, the light beam 13 is applied to the interface 10
To make p-polarized light incident on b, use a wave plate 1
The direction of the polarized light of No. 3 may be controlled.

Further, the surface plasmon measuring device 101 is
Signal processing units 20A, 20B, 20C of each measurement unit ...
It has one display means 21 connected to.

The sample analysis by the surface plasmon measuring device having the above structure will be described below.

As shown in FIG. 2, the light beam 13 emitted from the laser light source 14 is converged on the interface 10b between the dielectric block 10 and the metal film 12 through the incident optical system 15.

It converges on the interface 10b, and this interface 10b
The light beam 13 totally reflected by the collimator lens 1
It is detected by the photodetector 17 through 6. The photodetector 17 is a photodiode 17 which is a plurality of light receiving elements.
is a photodiode array in which a, 17b, 17c ... Are arranged side by side in a row, and the parallel arrangement of the photodiodes is performed through the collimator lens 16 such that the parallel arrangement direction of the photodiodes is substantially parallel to the paper surface of FIG. Incident light beam 1
It is arranged so as to be substantially orthogonal to the propagation direction of 3. Therefore, the different photodiodes 17a, 17b, 17c, ... Receive the respective components of the light beam 13 totally reflected at various reflection angles at the interface 10b. Then, the photodetector 17 outputs a signal indicating the intensity distribution of the light beam 13 detected by the photodiodes 17a, 17b, 17c ...

The component of the light beam 13 incident on the interface 10b at the specific incident angle θ _SP is the metal film 12 and the metal film 1.
Since surface plasmons are excited at the interface with the substance in contact with 2, the reflected light intensity sharply decreases for this light. That the specific incident angle theta _{S P} is attenuated total reflection angle, the reflected light intensity at the angle theta _SP indicates a minimum value. The region where the reflected light intensity decreases is observed as a dark line in the light beam 13 totally reflected at the interface 10b, as shown in FIG.

Next, the processing of the signal indicating the intensity distribution of the light beam 13 output from the photodetector 17 will be described in detail.

FIG. 4 is a block diagram showing the electrical configuration of this surface plasmon measuring device. As shown in the figure, the driver 19 is provided for each differential amplifier 18 of the differential amplifier array 18.
The sample-hold circuits 22a, 22b, 22c, which sample and hold the outputs of a, 18b, 18c ..., the multiplexer 23 to which the outputs of these sample-hold circuits 22a, 22b, 22c. A / D converter 24 which is converted to be input to the signal processing unit 20, a driving circuit 25 which drives the multiplexer 23 and the sample and hold circuits 22a, 22b, 22c ..., And a driving circuit 25 based on an instruction from the signal processing unit 20. It is composed of a controller 26 for controlling the operation of.

The above photodiodes 17a, 17b, 1
.. of the differential amplifier array 18 are input to the differential amplifiers 18a, 18b, 18c. At this time, the outputs of two photodiodes adjacent to each other are input to a common differential amplifier. Therefore, each differential amplifier 18
The outputs of a, 18b, 18c ... Are the photodetection signals output by the plurality of photodiodes 17a, 17b, 17c.
It can be considered that they are differentiated with respect to their juxtaposition direction.

Outputs of the differential amplifiers 18a, 18b, 18c, ... Are sample and hold circuits 22a, 22 respectively.
.. are sample-held at a predetermined timing by b, 22c, ... And inputted to the multiplexer 23. The multiplexer 23 uses the sample-and-hold differential amplifiers 18
Outputs a, 18b, 18c, ...
Input to the / D converter 24. The A / D converter 24 digitizes these outputs and inputs them to the signal processing unit 20.

FIG. 5 illustrates the relationship between the light intensity of the light beam 13 totally reflected at the interface 10b at each incident angle θ on the interface 10b and the outputs of the differential amplifiers 18a, 18b, 18c. is there. Here, it is assumed that the relationship between the incident angle θ of the light beam 13 on the interface 10b and the light intensity I of the reflected light beam 13 is as shown in the graph of FIG.

Further, FIG. 5B shows the photodiode 1
7a, 17b, 17c, ... Are shown in parallel, and as described above, these photodiodes 17a, 17b are provided.
The positions of b, 17c, ... Arranged in parallel are uniquely corresponding to the incident angle θ.

Then, the photodiodes 17a, 17b,
The relation between the positions of the 17c in parallel, that is, the incident angle θ, and the output I ′ (differential value of the reflected light intensity I) of the differential amplifiers 18a, 18b, 18c, ... Is as shown in FIG. It will be

The signal processing unit 20 receives from the A / D converter 24.
Based on the input differential value I ′, the differential amplifier 18
From a, 18b, 18c ...
Attenuation angle θ_SPThe differential value I '=
An output that is closest to 0 is obtained (example in Fig. 5 (3))
Then it becomes a differential amplifier 18e) and a negative value as a differential value
And the total reflection attenuation angle θ_SPDifferential value I'corresponding to
Output that is closest to = 0 (see (3) in FIG.
Select the difference amplifier 18d in the example), and select the difference between them.
The total reflection attenuation angle θ based on the differential value output from the dynamic amplifier
_SPTo calculate. In some cases, the differential value I ′ = 0
There may be a differential amplifier that outputs
Then the total reflection attenuation angle θ based on the differential amplifier_SPTo
calculate. After that, every time a predetermined time elapses, the same as above
Repeated operation, attenuated total reflection angle θ _SPTo calculate the measurement
The angle change amount from the beginning is calculated and displayed on the display means 21.

As described above, when the dielectric constant of the substance in contact with the metal film 12 of the measuring chip, that is, the refractive index changes,
Since the attenuated total reflection angle θ _SP also changes accordingly, the change in the refractive index of the substance in contact with the metal film 12 is investigated by continuously measuring the amount of change in the attenuated total reflection angle θ _SP over time. be able to.

When the sensing medium 30 that binds to the specific substance in the sample liquid 11 is fixed on the metal film 12, the refractive index of the sensing medium 30 changes depending on the binding state of the sample liquid 11 and the sensing medium 30. Changes, it is possible to check the state of change in the binding state by continuously measuring the differential value I ′. So in this case,
Both the sample liquid 11 and the sensing medium 30 serve as a sample to be analyzed. Examples of such a combination of the specific substance and the sensing medium 30 include an antigen and an antibody.

In the present embodiment, the holder may be constructed as shown in FIG. Holder 85 shown in FIG.
In comparison with the holder 80, the temperature control means is changed from the Peltier element 81 to the heat pipe 86.

A heat pipe 86 is provided inside the holder 85, and the heat pipe 86 is used as the heat source 8.
Connected to 7. The heat source 87 is the controller 8
8 and is controlled by this controller 88. Even in such a mode, the same effect as described above can be obtained.

Next, a second embodiment of the present invention will be described. The measuring apparatus according to the second embodiment is a surface plasmon measuring apparatus similar to the measuring apparatus according to the first embodiment, and FIG. 7 shows a side surface shape of the surface plasmon measuring apparatus. In FIG. 7, elements that are the same as the elements in FIG. 2 are given the same numbers, and descriptions thereof are omitted unless necessary.

Surface plasmon measuring device 1 of the present embodiment
02 differs from the surface plasmon measuring apparatus 101 of the first embodiment described above in that the measuring chip is held in the surrounding member instead of holding the measuring chip by the holder. The other configurations are basically the same as those of the surface plasmon measuring device 101 shown in FIG.

Each measuring unit of the surface plasmon measuring device 102 includes a measuring chip 9, an enclosing member 90 for spatially isolating the measuring chip 9 from the outside, and a laser light source 14 for generating a light beam 13. , The light beam 1
Incident optical system 15 for making 3 incident on the measuring chip 9
And a collimator lens 16 that collimates the light beam 13 reflected by the measurement chip 9 and emits the collimator lens 16 toward a photodetector 17, and receives the light beam 13 emitted from the collimator lens 16 to change the light intensity. A photodetector 17 for detecting, a differential amplifier array 18 connected to the photodetector 17, a driver 19 connected to the differential amplifier array 18, and a signal processing unit including a computer system connected to the driver 19 and the like. And 20. Further, the surface plasmon measuring device 102 includes the signal processing units 20A and 20A of the respective measurement units.
It has one display means 21 connected to B, 20C ...

The surrounding member 90 is made of a member having a high heat insulating property, such as resin or glass. Inside the enclosing member 90, a holding portion 90c for holding the measuring chip 9 is provided. Further, a lid 90b for inserting and removing the measuring chip 9 is provided on the upper surface of the surrounding member 90, and a Peltier element 91 is provided on the side surface as a temperature adjusting means. Further, an optical window 90a for transmitting the light beam 13 is provided on the side wall of the surrounding member 90 at a position corresponding to the optical path of the light beam 13.

A heat sink 92 is fixed to the side surface of the Peltier element 91. Further, the Peltier element 91 is connected to the controller 93, and this controller 93
Controlled by.

With the enclosing member 90 having such a structure, the measuring chip 9 can be shielded from the outside air, and heat can be uniformly conducted to the measuring chip 9 from a wide area of the measuring chip 9. Therefore, it is possible to adjust the temperature of the entire measuring chip 9 substantially uniformly.

In this embodiment, the surrounding member may have a structure as shown in FIG. Enclosing member 95 shown in FIG.
In comparison with the surrounding member 90, the temperature control means is changed from the Peltier element 91 to the heat pipe 96.

A heat pipe 96 is provided on the bottom surface of the surrounding member 95, and the heat pipe 96 is a heat source 9.
Connected to 7. The heat source 97 is the controller 9
8 and is controlled by the controller 98. Even in such a mode, the same effect as described above can be obtained.

In the surface plasmon measuring device described in the first and second embodiments, instead of performing the sample analysis by detecting the position of the dark line of the light beam reflected by the interface, the light beam is applied to the interface. At the angle of incidence at which the total reflection condition is obtained, a part of this light beam is
This light beam is divided before entering the interface, the divided light beam is caused to interfere with the light beam totally reflected at the interface, and the intensity of the light beam after the interference is measured to analyze the sample. You can also do it.

A description will be given below with reference to the drawings. FIG. 9 is a view showing a side surface shape of the surface plasmon measuring device 101 ″. In this figure, the holder or the surrounding member and the temperature adjusting means associated therewith are omitted.

As shown in FIG. 9, the surface plasmon resonance measuring apparatus 101 ″ has the interference optical system 5 instead of the incident optical system 15 from the surface plasmon resonance measuring apparatus 101.
It is changed to 0.

Light beam 1 emitted from laser light source 14
3 is collimated by the collimator lens 50a and enters the polarization filter 50b. The light beam 13 transmitted through the polarization filter 50b and incident on the interface 10b as p-polarized light is partially split as a reference light beam 13R by the half mirror 50c, and the remaining light that has passed through the half mirror 50c. Beam 13S is interface 10b
Incident on. The light beam 13S totally reflected by the interface 10b and the reference light beam 13 reflected by the mirror 50e
R enters the half mirror 50d and is synthesized. The combined light beam 13 'is condensed by the condenser lens 50f, passes through the aperture 50g, and is detected by the CCD 60. At this time, the light beam 13 'detected by the CCD 60 is the light beam 13S and the reference light beam 1
Interference fringes are generated according to the state of interference with 3R.

That is, in this case, when the permittivity of the material in contact with the metal film 12 of the measuring chip 9 or the refractive index changes, the light beam 13S and the reference light beam 13R totally reflected at the interface 10b are reflected by the half mirror 50d. Since the state of interference changes when they are combined, it is possible to detect a change in the refractive index of the substance in contact with the metal film 12 according to the change in the interference fringes.

Further, the above-mentioned surface plasmon measuring device is
A leaky mode measuring device can be obtained by changing a part of the configuration. FIG. 10 is a side view of a measurement unit of a leaky mode measuring device 201 configured by partially modifying the surface plasmon measuring device 101 described above as an example.
Note that, in FIG. 10, elements that are the same as the elements in FIG. 2 are given the same numbers, and descriptions thereof are omitted unless necessary.

This leaky mode measuring device is also configured to use the measuring chip 9 similarly to the above-mentioned surface plasmon measuring device. A clad layer 40 is formed on the bottom surface of the recess 10c formed on the upper surface of the measurement chip 9, and an optical waveguide layer 41 is further formed on the clad layer 40. The clad layer 40 and the optical waveguide layer 41 form a thin film layer.

The dielectric block 10 is made of, for example, synthetic resin or optical glass such as BK7. On the other hand, the clad layer 40 is formed into a thin film using a dielectric material having a lower refractive index than the dielectric block 10 or a metal such as gold. The optical waveguide layer 41 is also formed in a thin film using a dielectric material having a higher refractive index than the cladding layer 40, for example, PMMA. The film thickness of the clad layer 40 is, for example, 36.5 nm when it is formed of a gold thin film, and the film thickness of the optical waveguide layer 41 is approximately 700 nm when it is formed of PMMA.

In the leaky mode measuring device having the above structure,
When the light beam 13 emitted from the laser light source 14 is incident on the cladding layer 40 through the dielectric block 10 at an angle of incidence equal to or more than the total reflection angle, many components of the light beam 13 are included in the dielectric block 10 and the cladding layer. Interface 10 with 40
Light having a specific wave number, which is totally reflected by b but is transmitted through the cladding layer 40 and is incident on the optical waveguide layer 41 at a specific incident angle, is propagated in the optical waveguide layer 41 in a waveguide mode. When the guided mode is excited in this way, most of the incident light that has entered at the specific incident angle is taken into the optical waveguide layer 41, so that the intensity of the light that is incident on the interface 10b at the specific incident angle and totally reflected is sharp. Decreasing total internal reflection attenuation occurs.

Since the wave number of guided light in the optical waveguide layer 41 depends on the refractive index of the sample liquid 11 on the optical waveguide layer 41,
By knowing the attenuated total reflection angle, which is the specific incident angle at which the attenuated total reflection occurs, the refractive index of the sample liquid 11 and the characteristics of the sample liquid 11 related thereto can be analyzed. The effect can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing a schematic configuration of a surface plasmon measuring device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a side surface shape of the surface plasmon measuring device according to the first embodiment.

FIG. 3 is a schematic configuration diagram of a measurement chip.

FIG. 4 is a block diagram showing an electrical configuration of a surface plasmon measuring device.

FIG. 5 is a diagram showing a relationship between an incident angle of a light beam on an interface and an output of a differential amplifier.

FIG. 6 is a diagram showing a side surface shape of another surface plasmon measuring device according to the first embodiment.

FIG. 7 is a diagram showing a side surface shape of a surface plasmon measuring device according to a second embodiment.

FIG. 8 is a diagram showing a side surface shape of another surface plasmon measuring device according to the second embodiment.

FIG. 9 is a view showing a side surface shape of a surface plasmon measuring device.

FIG. 10 is a diagram showing an example of a leak mode measuring apparatus.

[Explanation of symbols]

9 Measuring Chip 10 Dielectric Block 13 Light Beam 14 Laser Light Source 15 Incident Optical System 16 Collimator Lens 17 Photodetector 18 Differential Amplifier Array 19 Driver 20 Signal Processing Unit 21 Display Means 50 Interfering Optical System 60 CCD 61 Signal Processing Unit 70 Sheath 80, 85 Holder 90, 95 Enclosing member 101 Surface plasmon measuring device 101A, 101B, 101C ... Surface plasmon measuring unit 201 Leakage mode measuring device

Claims (3)

[Claims] 1. A measuring chip comprising a dielectric block, a thin film layer formed on one surface of the dielectric block, and a sample holding mechanism for holding a sample on the surface of the thin film layer, and a light beam is generated. A light source, an incident optical system that causes the light beam to be incident on the dielectric block at an incident angle such that total reflection conditions are obtained at an interface between the dielectric block and the thin film layer, and light totally reflected at the interface A measuring device comprising a light detecting means for measuring the intensity of a beam, comprising a member having a higher thermal conductivity than the dielectric block, which holds the measuring chip in surface contact with the dielectric block. A holder is provided, and the holder is provided with at least an optical window arranged on the optical path of the light beam, and a temperature adjusting means for adjusting the temperature of the measuring chip via the holder. A measuring device characterized in that 2. A measuring chip comprising a dielectric block, a thin film layer formed on one surface of the dielectric block, and a sample holding mechanism for holding a sample on the surface of the thin film layer, and a light beam is generated. A light source, an incident optical system that causes the light beam to be incident on the dielectric block at an incident angle such that total reflection conditions are obtained at an interface between the dielectric block and the thin film layer, and light totally reflected at the interface A measuring device comprising a light detecting means for measuring the intensity of a beam, comprising an enclosing member for spatially isolating the measuring chip from the outside, the enclosing member being disposed at least on the optical path of the light beam. A measuring device comprising an optical window and a temperature adjusting means for adjusting the temperature in the surrounding member. 3. The measuring chip used in the measuring device according to claim 1, wherein the outer surface of the dielectric block is provided with a sheath composed of a member having a heat capacity larger than that of the dielectric block. A measuring chip characterized by being.